Michael Kennedy, a 33-year-old Marine veteran from Hyde Park, was pulled from the basement at the rear of the building. He was transported to Mass General Hospital where he was pronounced dead.

Lt. Edward Walsh, 43 of West Roxbury, was also found in the basement. He was pronounced dead at the scene. He leaves behind a wife, and three children under the age of 10.

Both Walsh and Kennedy worked on Engine 33/Ladder 15 out of the station at Boylston and Hereford streets. They were among the first firefighters at the scene after the fire was reported Wednesday afternoon around 2:43 p.m.

Deputy Chief Finn told reporters he believes Walsh and Kennedy took a line into the basement, where officials believe the fire started, and became trapped. Kennedy was located about 30 minutes into the fire. Walsh was not pulled from the building until hours later.

Walsh had been with the department for nine years, Kennedy for six.

“Words cannot do justice to the grief that we feel tonight,” Mayor Martin Walsh said in a statement shortly after speaking at the press conference. “Our hearts are heavy with the knowledge that these brave men gave their lives to protect the safety of our city and its people.”

Thirteen other firefighters were injured fighting the blaze. Boston Fire officials said those injuries include burns and broken bones, but are not life-threatening.

Officials said a number of residents were rescued from the top floors of the building.

“Citizens were saved, and that’s what we do,” Richard Paris, president of the local firefighters union, said during the press conference. “We sacrifice our life for the citizens of Boston.”

Firefighters expected to be at the scene through the night working to extinguish the last flames.